#top{
    width: 780px;
    height: 183px;
    margin-bottom: 2px;
}
#ban{
    width: 780px;
    height: 150px;
    background: url(../img/banner.jpg) no-repeat;
}
#nav li{
    float: left;
    text-align: center;
    line-height: 33px;
    width: 78px;
}
#nav a{
    background: url(../img/button1.jpg);
    display: block;
    background-color: #004A87;
}
#nav a:hover{
    background: url(../img/button1_bg.jpg);
    position: relative;
    bottom: 1px;
    right: 1px;
}